Which component is NOT typically found in a machine gun?

In the context of a machine gun's design and functionality, a smart sighting device is not typically a standard component. Machine guns are primarily constructed with several essential parts that facilitate their operation, including the receiver, barrel, and feed mechanism.

The receiver is the core structure that houses the operational parts of the machine gun, providing a framework for assembling the weapon. The barrel is essential for directing the projectile and is designed to withstand the high pressures generated upon firing. The feed mechanism is crucial as it ensures a continuous supply of ammunition to the weapon, allowing for sustained fire.

While modern advancements in weaponry may integrate advanced sighting systems or optics into firearms, a smart sighting device is not a basic or inherent part of a machine gun's construction. Machine guns traditionally rely on simpler aiming devices, such as iron sights or basic optical sights. Therefore, the absence of a smart sighting device as a standard component makes it the correct choice in this instance.